// Copyright 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_GFX_GEOMETRY_INSETS_BASE_H_
#define UI_GFX_GEOMETRY_INSETS_BASE_H_

#include "ui/gfx/gfx_export.h"

namespace gfx {

// An insets represents the borders of a container (the space the container must
// leave at each of its edges).
template <typename Class, typename Type>
class GFX_EXPORT InsetsBase {
public:
    Type top() const { return top_; }
    Type left() const { return left_; }
    Type bottom() const { return bottom_; }
    Type right() const { return right_; }

    // Returns the total width taken up by the insets, which is the sum of the
    // left and right insets.
    Type width() const { return left_ + right_; }

    // Returns the total height taken up by the insets, which is the sum of the
    // top and bottom insets.
    Type height() const { return top_ + bottom_; }

    // Returns true if the insets are empty.
    bool empty() const { return width() == 0 && height() == 0; }

    void Set(Type top, Type left, Type bottom, Type right)
    {
        top_ = top;
        left_ = left;
        bottom_ = bottom;
        right_ = right;
    }

    bool operator==(const Class& insets) const
    {
        return top_ == insets.top_ && left_ == insets.left_ && bottom_ == insets.bottom_ && right_ == insets.right_;
    }

    bool operator!=(const Class& insets) const
    {
        return !(*this == insets);
    }

    void operator+=(const Class& insets)
    {
        top_ += insets.top_;
        left_ += insets.left_;
        bottom_ += insets.bottom_;
        right_ += insets.right_;
    }

    Class operator-() const
    {
        return Class(-top_, -left_, -bottom_, -right_);
    }

protected:
    InsetsBase(Type top, Type left, Type bottom, Type right)
        : top_(top)
        , left_(left)
        , bottom_(bottom)
        , right_(right)
    {
    }

    // Destructor is intentionally made non virtual and protected.
    // Do not make this public.
    ~InsetsBase() { }

private:
    Type top_;
    Type left_;
    Type bottom_;
    Type right_;
};

} // namespace gfx

#endif // UI_GFX_GEOMETRY_INSETS_BASE_H_
